I think that hyphenation - simply acts to separate the word play, the first part of the clue, from the definition, the second part of the clue.
So we have success meaning luck, limits, splitting luck into the limits of the solution so lu appears at start and ck at the end. We then insert g for good and use the letters in garage as an anagram (indicated by busy) to arrive at complete answer i.e. luggage rack. I hope this explains the answer more fully.
Andy